What the Web Server Surveys
Reveal

ApacheWeek has often reported on the success of the Apache
Web Server as shown by the E-Soft Web Server and Netcraft surveys, and how
they have consistently shown Apache to be the most popular
and more widely deployed server than all the others combined.

In this 200th issue of ApacheWeek, we look behind the
headline figures of those surveys with an in-depth analysis
of which Apache versions are being used and how long it takes
the Apache community to adopt new releases.

Although both surveys show the total number of sites using
Apache, the E-Soft survey figures also reveal some
interesting facts about which versions of Apache are in use,
and that take up of newer releases is not immediate. Plotting
the number of sites using 1.3.x versions month for month from
release date indicates migration from older versions is slow.
As a percentage of Apache powered sites, in the case of
almost all versions, their use continues to remain constant
for a few months even after a new release. Take into account
the number of sites using Apache is increasing every month;
and the actual number of sites using older releases continues
to rise for anything up to three months after a new release
becomes available.

It wasn't until April this year, with Apache 1.3.9 released 9
months earlier, that the use of a single 1.3 version exceeded
that of older 1.1 and 1.2 versions. Even today, only 6% of
sites are using the most recent release, 1.3.12, and over 25%
of sites are still powered by older Apache versions from the
1.0, 1.1, and 1.2 generations.

One of the most interesting findings from the survey is to
see how new releases may influence the take-up of Apache as a
server. Looking at the monthly increase in the number of
sites powered by the server, some of the largest rises follow
particular release dates.

The month following the release of Apache 1.3.3 (released on
October 9 1998) saw one of the highest monthly increases in
use. Apache 1.3.3 was a minor upgrade to Apache 1.3.2, but
fixed one quite important problem; various error responses,
such as "404 Not Found" displayed the full path to the
missing file. Other problem fixes included the spelling
module - which in 1.3.2 did not return the list of possible
matches when more than one file is similar to the requested
URL - and a problem where missing .htaccess files could
result in a "Forbidden" response. Some platform specific bug
fixes - including the Windows zombie processes problem - were
also fixed.

Apache 1.3.12, the most current version, has also seen a huge
increase in use in the month following its release. This
addressed security issues raised by a CERT advisory on
cross-site scripting which wasn't specific to Apache and had
wide reaching consequences for anyone who uses or writes
scripts for web servers. Patches were quickly made available
for the previous version (1.3.11) followed shortly afterwards
with the release of 1.3.12 at the end of February. Once
again, it was shown that the contributors to open source
projects can respond as efficiently as commercial developers
to major security issues.

The surveys can't tell us whether the increases are
attributable to upgraders or new adopters, and it is purely
speculative as to whether the rapid provision of a security
fix to a problem contributed to the migration from other
servers to Apache. However, the E-Soft Survey shows there was
an increase of 76,000 sites using Apache in March 2000, and
36,000 sites using 1.3.12.

What can not be disputed is the phenomenal success of the
Apache web server, now with a share of the server software
market that commercial vendors only dream of. Whichever
version is in use, it's all part of the ever-growing Apache
community which Apache Week will continue to support.